Automatic slack-adjuster.



G. SGHENGK. AUTOMATIC SLAGKI ADJUSTER.

APPLICATION FILED AUG. 29, 1910.

Patented June 27, 191 1.

lj/yoaea UNITED. STATES mm: OFFICE.

CHARLES SCHENCK, CHICAGO, ILLINOIS, ASSIGNOR TO TRANSPORTATION APPLI- ANCE CORPORATION, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

' AUTOMATIC SLACK-ADJUSTER.\

justers, of which the'following is a speci fication.

This invention relates to improvements in automatic slack adjusters which are used in air brake mechanism in cars, trains, etc.

The object of this invention is to provide a simple, economical, durable and efficient device in which the piston travel in the air brake cylinder may be at all times automatically controlled and adjusted in such manner as to provide a means of positively taking up slack in the airbrake rigging due to the ordinary wear and tear of same and particularly wear upon brake shoes, and other travel of brake rigging due to wear upon pins in links of same.

The utility of this device is providing a means for automatically adjusting the slack by means of the over travel of the piston in the air cylinder as hereinafter described.

The invention consists in features of construction and combination of parts hereinafter described and claimed.

In the drawings Figure 1 is a side-elevation, partly in section, showing the construction of the brake cylinder with slack ad juster attached thereto; Fig. 2 a detail showing serrated edgeson piston; and Fig.3 a detail end view looking in upon rigging mechanism applied to brake cylinder. Referring to Fig. 1, attached to the standard brake cylinder 4 is shown a brake rigging having rocker arms 5 and. 6, connecting rod 7 and outer brake levers 8 and 9 respectively. The brake cylinder 4, as shown, com prises a main body 10 with opposite end castings 11 and 12 respectively. Part of the main body of the cylinder 10 is cut away to show its interior which is preferably made in accordance with standard practice and construction, having a piston spring 13 and piston rod 14 in which a push rod 15 travels. Attached to or formed'with the end casting 12 is an extended frame 16, carrying an engaging traveler 17 provided with opposite projecting shoulders 18 and 19. The base of the traveler 17 is recessed, as shown, at 20 on opposite sides for its entire length for Specification of Letters Patent. Application filed August 25, 1910. Serial No. 579,392.

Patented J une27, 1911;

the purpose of movably securing the traveler j-ecting frame 16, as shown in Fig. 3. The ju-nderface of the traveler is provided with serrated edges 22 which a ,dog 23 may engage during the-forward movement of the traveler 17. The dog is held in closed position as indicated by a leaf spring 24 which is secured to the under face of the frame 16.

Pivotally secured to the rocker, arm 6at its lower end 25 is the push rod 15, the uppreferably, with serrated edges allow engagement by; a set of double opposed spring actuated jaws 28. The teeth of the jaws come into positive engagement with the said recesses in the upper and lower faces of the push rod and are retained in position therewith by means of a coiled spring 29. The double acting jaws with the spring retainer are forinedlntegrally with or attached to an annular collar 30 mounted on the end of the piston rod 14 adjacent the end casting 12.

The space or allowance for lateral move -ment between the shoulders 18 and 19 may be made to suit operating conditions as the equivalent of the normfilspiston travel in the standard brake cylinder, for instancepfour or six' inches as the ie'ase may be. In the 'operation of the cylinder air is admitted through an air supp-ljrEpipe 31 under pressure from'the car reservoir, or otherwise,

its forward movement by the air pressure therein. In normal position, as in the case of the first setting'of the air brake shoes and rigging theshoulder 18 is set with reference to the push rod 15 so that they come into engagement at the end of the stroke of the piston. Due to an uneven wear on the brake shoes, or because of lost motion in journals, brasses, center plates and variations in total leverages the push rod 15 has a 'tendency for increased travel which causes the shoulder 18 on the traveler 17 to be moved outwardly and as this traveler moves forward the dog 28 comes into engagement with the toothed-or serrated edge 22 on the 'under face of the traveler which prevents its return toward the brake cylinder proper. As the piston returns on its back stroke the pin 25 comes into engagement against the shoulder 19 which causes a lengthening of within the lower flanged base 21 of the pro and the piston is actuated in the cylinder in per and lower faces of which are provided,

27 which the push rod to compensate for the increased length of piston travel, so that the slack in the brake'rigging is automatically adjusted. It is obvious that'the construction of the device, or parts thereof, may be somewhat altered or modified if desired without departing from the spirit of the invention.

a Without specifically limiting myself to the aforesaid construction I claim:

1. In combination with a brake cylinder, an automatic slack adjuster comprising a movable traveler, a push rod provlded with upper and lower serrated edges, the outer end of the push rod being secured to a rocker arm, gripping jaws for engaging the push rod, means for retaining the traveler-in de sired position with respect to the push rod and means for automatically permitting oi the lengthening of the ush rod to compensate for the increased liength of the piston travel to take u slack in the brake mechanism, substantia ly as described.

A 2. In combination with a brake cylinder,

an automatic slack adjuster comprising a movable traveler provided with oppositely formed shoulders, airame provided with a recessed base for engagement with the o positely formedshoulders of the movab e traveler, the under side of the traveler being provided with serrated edges, a dog positioned adjacent the serrated edges for engagement therewith, a push rod secured at traveler for automatically permitting of the lengthening of the push rod to compensate for the increased-length of piston travel to take up slack in the brake mechanism, substantially as described.

' CHARLES SCHENGK. Witnesses:

WALKER BANNING, MARY R. Fnos'r. 

